在 32 位 armv7 上报错 panic: unaligned 64-bit atomic operation

[Eson-Jia]

What happened:

2022-03-15T16:12:32.497+0800    INFO     nacos_client/nacos_client.go:79 logDir:</root/log>   cacheDir:</root/cache>
2022-03-15T16:12:32.500+0800    INFO     nacos/builder.go:138    [Nacos Client] New nacos client with config = [{Scheme: ContextPath: IpAddr:192.168.1.72 Port:8848}]
2022-03-15T16:12:32.501+0800    INFO     v3router/router_chain.go:55     [NewUniformRouterChain] Config center does not start, please check if the configuration center has been properly configured in dubbogo.yml
panic: unaligned 64-bit atomic operation

goroutine 132 [running]:
runtime/internal/atomic.panicUnaligned()
        /home/ubuntu/BMI-HI3521A/go/src/runtime/internal/atomic/unaligned.go:8 +0x24
runtime/internal/atomic.Store64(0x45720ac, 0x3b9aca00)
        /home/ubuntu/BMI-HI3521A/go/src/runtime/internal/atomic/atomic_arm.s:301 +0x14
go.uber.org/atomic.(*Int64).Store(...)
        /StreamPlugins/gopath/pkg/mod/go.uber.org/atomic@v1.9.0/int64.go:75
go.uber.org/atomic.(*Duration).Store(...)
        /StreamPlugins/gopath/pkg/mod/go.uber.org/atomic@v1.9.0/duration.go:55
github.com/apache/dubbo-getty.(*gettyConn).SetWriteTimeout(0x4572080, 0x3b9aca00)
        /StreamPlugins/gopath/pkg/mod/github.com/apache/dubbo-getty@v1.4.7/connection.go:161 +0x6c
github.com/apache/dubbo-getty.newSession({0x1466f7c, 0x436e1e0}, {0x1476284, 0x4572080})
        /StreamPlugins/gopath/pkg/mod/github.com/apache/dubbo-getty@v1.4.7/session.go:151 +0x1b4
github.com/apache/dubbo-getty.newTCPSession({0x1469bb8, 0x43c6a08}, {0x1466f7c, 0x436e1e0})
        /StreamPlugins/gopath/pkg/mod/github.com/apache/dubbo-getty@v1.4.7/session.go:159 +0x48
github.com/apache/dubbo-getty.(*client).dialTCP(0x436e1e0)
        /StreamPlugins/gopath/pkg/mod/github.com/apache/dubbo-getty@v1.4.7/client.go:170 +0x400
github.com/apache/dubbo-getty.(*client).dial(0x436e1e0)
        /StreamPlugins/gopath/pkg/mod/github.com/apache/dubbo-getty@v1.4.7/client.go:346 +0x38
github.com/apache/dubbo-getty.(*client).connect(0x436e1e0)
        /StreamPlugins/gopath/pkg/mod/github.com/apache/dubbo-getty@v1.4.7/client.go:384 +0x48
github.com/apache/dubbo-getty.(*client).reConnect(0x436e1e0)
        /StreamPlugins/gopath/pkg/mod/github.com/apache/dubbo-getty@v1.4.7/client.go:441 +0x90
github.com/apache/dubbo-getty.(*client).RunEventLoop(0x436e1e0, 0x43c69d8)
        /StreamPlugins/gopath/pkg/mod/github.com/apache/dubbo-getty@v1.4.7/client.go:419 +0x70
created by dubbo.apache.org/dubbo-go/v3/remoting/getty.newGettyRPCClientConn
        /StreamPlugins/gopath/pkg/mod/dubbo.apache.org/dubbo-go/v3@v3.0.1/remoting/getty/pool.go:79 +0x444```
**What you expected to happen**:

**How to reproduce it (as minimally and precisely as possible)**:

**Anything else we need to know?**:
go version 1.17.7  dubbo-go version 3.0.1

[LaurenceLiZhixin]

That's a good problem.

[baerwang]

https://www.pengrl.com/p/21030/

[LaurenceLiZhixin]

Any more questions? This issue will be closed @Eson-Jia

[Eson-Jia]

我发现如果注册中心是 nacos ，在 32 位的 armv7 上运行的 dubbo-go(v3.0.1) cilent 启动后就会崩溃。如果将注册中心改成 zookeeper，cilent 就不会崩溃。目前的解决方法是使用 zookeeper 作为注册中心。 @LaurenceLiZhixin

[binbin0325]

看panic堆栈比较明显。这是因为在dubbo-getty connection.go的SetWriteTimeout()中使用了uber atomic.Store, 在Store中会对val转换int64，导致在32位操作系统panic.

go.uber.org/atomic.(*Int64).Store(...)
        /StreamPlugins/gopath/pkg/mod/go.uber.org/atomic@v1.9.0/int64.go:75
go.uber.org/atomic.(*Duration).Store(...)
        /StreamPlugins/gopath/pkg/mod/go.uber.org/atomic@v1.9.0/duration.go:55
github.com/apache/dubbo-getty.(*gettyConn).SetWriteTimeout(0x4572080, 0x3b9aca00)

func (x *Duration) Store(val time.Duration) {
	x.v.Store(int64(val))
}

uber-go/atomic issue:uber-go/atomic#105